It is currently common to equip motor vehicles with airbag devices. Such devices are generally housed in vehicle dashboards, while being hidden under a lining element covering the dashboard. Such a lining element may be of the type comprising a rigid support element and a covering element covering the support element, the covering element comprising a skin intended to be visible to an occupant of the passenger compartment of the motor vehicle, the support element defining at least one opening for the deployment of an airbag toward the outside of the lining element, a frame being connected to the support element and extending around the periphery of the opening, the frame carrying a continuous rib extending from the frame into the covering element, along at least a part of the periphery of the opening.
When it is deployed, the airbag must therefore pass through the lining element covering it, which is generally done by tearing of part of the covering element, thereby freeing a passage for the airbag toward the passenger compartment. The lining element must therefore be designed to tear cleanly so as to allow an optimal deployment of the airbag and prevent material from being projected from the covering element into the passenger compartment, those projections potentially hurting the occupants of the vehicle.
To that end, it is known to create a weakening area in the covering element so as to limit tearing. When the airbag is deployed, it acts on a flap which in turn acts on the weakening area, which makes it possible to control the tearing.
However, the tearing is not always optimally controlled and risks often remain of projections entering the passenger compartment.
It is known from US-2009/0309338 to provide a rigid rib extending over at least part of the periphery of the deployment opening of the airbag, to improve the tearing of the covering element during deployment of the airbag.
However, there is a risk that, in case of impact against the surface of the lining element, for example if the head of an occupant of the vehicle collides with the lining element, the rib sections the covering element and emerges in said outer surface, which would risk causing injuries to that occupant.